Receivers for satellite television generally comprise a parabolic dish having a dipole at its centre to collect the high frequency electro-magnetic radiation transmissions from a satellite television transmitter in geostationary orbit. The effectiveness of reception by the receiver is heavily reliant upon maintenance of alignment of the dish with the transmitter. This poses a considerable problem where the satellite receiver dish is mounted to a vehicle or vessel, such as a ship, which is moving relative to the surface of the earth.
Amongst the systems which have been developed to overcome this problem are a simple gyroscopic mounting for use on sea-going vessels to compensate for rolling motion of the vessel, and a system which has been developed for use on buses which comprises a sensory device having three zones positioned to enable detection of two axes of skew of the signal received from the transmitter by comparing the time delay in reception of signal by each of the zones. Neither of these systems is suitably rapid, efficient and effective in operation.